| In the actual production problem,for the welding defects of aerospace aluminum alloy on the traditional fusion welding,the solid phase connection technology of friction stir welding(FSW)is adopted to improve the surface quality of the post-weld and the quality of the welded joint.The specific welding parameter range is the most important influencing factor affecting the FSW welding effect of the same kind of aluminum alloy,but for the different types of different strength aluminum alloy FSW welding,due to the difference in the properties of different series of different types of aluminum alloy materials,the same welding The welding results obtained under the parameters will vary greatly;and the welding method,such as the offset position of the agitating needle and the type of material on the advancing side,will affect the actual welding effect.Excellent joint performance is the basis of industrial application.In order to explore the optimal welding parameters range and the best welding method of aluminum alloy in FSW,it is developed around 5A06 aluminum alloy and 5A06/7005 dissimilar aluminum alloy FSW flat welding experimental study.(1)The movement mode and specific force of the mixing head during FSW were studied.The calculation method of friction stress in different welding stages is mainly studied.As the non-negligible adhesive friction in the stress process,the specific analysis is carried out during the force analysis.The force analysis of this part lays down the heat generation equation basis.(2)The heat generation method in the FSW process was analyzed,and the specific heat production equation was established.Based on this equation,Abaqus was used to simulate the temperature of the 5A06 aluminum alloy FSW plate docking process.The results were analyzed by using the same parameters.The temperature change mode at the specific position of the plate provides a deep understanding of the temperature change trend during the FSW process,and determines the reasonable welding parameter range,which lays a foundation for the subsequent welding experiment.(3)The FSW homogenous material docking test was carried out on a 6mm thick 5A06 aluminum alloy plate within a certain parameter range.The temperature measurement test was carried out at the specified point under the exact parameters,and the accuracy of the heat generation model was verified.The macroscopic and microscopic surface forming,joint strength,joint fracture form,metallographic structure change and.FSW welding after different parameters were analyzed.The experimental indexes such as hardness are used to obtain the optimal combination of parameters under different test indexes.(4)The FSW test process of 5A06/7005 dissimilar aluminum alloy was studied.The differences of surface molding after welding and welding of dissimilar and same materials were compared.The effects of test parameters and welding methods on different surface indexes,joint strength,metallographic structure and hardness were investigated.The optimal parameter range was obtained and the best way to solder.(5)The effects of different parameters and welding methods on the flow and mixing form of the material at the weld joint of the 5A06/7005 dissimilar aluminum alloy flat plate were analyzed.The flow pattern of the material around the mixing needle was explored to obtain the best material.The range of process parameters and the welding method in the mixed form. |
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